. The major research focus of this OAIC is on the reduction of physical frailty resulting in a decrease in the risk of loss of independence and nursing home admission. The goals of this intervention study, IS-1, are: a) to determine the extent to which frail women and men over the age of 78 years can respond to exercise training with the cardiovascular, skeletal muscle, and central nervous system adaptations that have been shown to occur in younger individuals; and b) if significant adaptations do occur, to assess whether or not the magnitudes of these adaptations are sufficiently large and functionally important to result in improvements in performance of activities of daily living (ADL), instrumental ADL (IADL), advanced ADL (AADL) and in objective physical performance tests that correlate with the ability to perform IADL and AADL and are predictors of loss of independence, nursing home admission, and short- term mortality. The long-term goal is to obtain information that can be used to design practical, individualized programs of exercise that can be utilized in community settings to prevent or reverse physical frailty and maintain functional independence. The exercise training will have three phases consisting of 3 months of physical therapy exercises, 3 months of weight lifting superimposed on physical therapy exercises, and 3 months of aerobic exercise superimposed on physical therapy and weight lifting exercise. The aims of this research are to determine: a) the effectiveness of physical therapy exercises in improving flexibility, gait, balance, coordination, and strength and in reversing frailty; b) whether frail old people can adapt to weight lifting with significant increases in strength of all major muscle groups, whole body and skeletal muscle protein anabolism, and muscle mass, and a further reduction in frailty; c) whether frail old people can adapt to aerobic exercise training with increases in oxygen uptake capacity with a further decrease in frailty, and to evaluate the mechanisms involved in any increase in oxygen uptake capacity by determining maximal cardiac output, left ventricular stroke volume, and peripheral oxygen extraction; d) whether the exercise training decreases arterial stiffness; e) whether exercise training lowers blood pressure in subjects with mild hypertension; f) whether the exercise increases bone mineral density in the proximal femur, spine, and other regions of the skeleton; g) whether the exercise improves cognitive function and central processing speed; and h) whether the exercise improves quality of life. An important component of this research is to determine the extent to which the graduates from the program maintain improvements in functional capacity. Before discharge from the study, participants will be given individualized exercise prescriptions to follow at home and will be helped to put together home gyms or referred to a convenient exercise facility. Contact with the graduates will maintained by means of monthly phone calls and they will be brought back to the exercise facility once per month for a training session and periodic evaluations of functional capacity, using simple measures such as the standardized Physical Performance Test. Cost-effectiveness and cost-utility analysis will be used to evaluate the relative costs and benefits of the exercise.